The United States is "doing the right thing" by pursuing a diplomatic solution to the threat that Iran may soon gain a nuclear weapon, but the world cannot afford to wait too long, Israel's defense minister said Tuesday.

Israeli Defense Minister Ehud Barak said he supports the U.S. focus on tougher economic sanctions against Tehran and that the United States is the only world power that can muster a coordinated global effort to deter Iran through economic pressure.

"Only time will tell to what extent they are really effective," Barak said following meetings at the Pentagon with the top U.S. civilian and uniformed officials. He warned that if the international community waits too long, Iran could acquire a nuclear weapon that would "change the landscape" of the entire world, not just of the Middle East.

U.S. defense officials walk a fine line when discussing Iran and Israel, quick to say that a nuclear Iran is intolerable and a direct threat to Israel, but also firm that a pre-emptive U.S. or Israeli military strike would be counterproductive now.

Defense Secretary Robert Gates warned in a secret memo in January that the United States needed more forethought and more options as Iran edges closer to the time when it could build a weapon. He declined to go further Tuesday.

"I'm very satisfied with the planning process" at the Pentagon and elsewhere within the Obama administration, Gates said during a news conference with Barak. "We spend a lot of time on Iran, and we'll continue to do so."

Iran and the rearming of the Hezbollah militia were major topics of Barak's session at the Pentagon. He met earlier Tuesday with Secretary of State Hillary Rodham Clinton.

Barak's three-day visit to Washington is partly intended to project a better image of U.S.-Israeli relations than what emerged from the tense visit of Israeli Prime Minister Benjamin Netanyahu last month.

The traditionally close alliance between United States and Israel has been strained by the Netanyahu government's move to expand Jewish housing on land claimed by Palestinians for their future capital. The United States sees the move as a direct affront to peacemaking. Peace talks remain stalled.